Screeding apparatus

ABSTRACT

An apparatus for pivoting a screed assembly during screeding of placed and/or poured, uncured concrete or like loose, spreadable materials to maintain proper screeding contact by the screeding assembly with the concrete or like material by maintaining the predetermined levels of concrete or other like material acting against the screed assembly as it is moved along the concrete. The apparatus requires a support preferably of the self-propelled type, having a boom and a boom mount. The axis of the pivot extends generally perpendicularly to the screeding direction in which the screed assembly is moved. A power source, such as a fluid cylinder rotates the screed about the pivot axis, preferably in response to a leveling sensor mounted on the screed. The lateral incline of the screed perpendicular to the screeding direction may also be separately controlled. A power operated elevation control is preferably responsive to a fixed laser beam reference plane positioned externally of the screed assembly. The screed preferably includes a novel lightweight and is vibrated electrically rather than mechanically vibration assembly is vibrationally isolated from the remainder of the screed for smoothing the concrete.

BACKGROUND OF THE INVENTION

The invention is an improved screeding apparatus for attachment to aboom from a power unit. The improvement includes a screed assembly whichis light weight and unitary, i.e. rigid framework and operable units,i.e. striker, rotatable auger means for moving the material in directionof auger screw, and vibrating means for engaging, vibrating andsmoothing the material, are always on one plane.

The screed assembly is mounted to pivot about the axis of a rotatableauger means whereby controlled contact of the striker and vibrationmeans is or may be controlled by rotation of the screed assembly aboutthe axis of the auger means whereby the contact of the striker and thevibration unit and the auger means with the material is on one plane.Elevation means for raising and lowering the screed assembly withrespect to material to be smoothed. This is accomplished by theelevation means which is operable in response to fixed laser beam orbeams, so that the screed may have the plane of the screed assemblyparallel to the auger means modified to control the elevation and gradein conjunction with the controlled rotation of the screed assembly.

This results in the lateral tilt of the screeding assembly as well asfor the plane of the striker, auger and vibration means.

The elevation control tubes or means are secured directly to the ends ofthe screed assembly so that the plane of the screed assembly is at rightangles to the direction of movement of the screed assembly.

Sensing means including setting of desired values of grade and/orelevation of the screed with reference to the material are an integralpart of the screed assembly. To ascertain variations from the settingsof the elevation and or grade the sensor will signal the elevation unitsand the rotational unit to planes not units of change to maintain thedesired elevation and grade.

The screeding apparatus of this invention provides improvements andadvantages over prior screeding assemblies.

The unitary structure of this novel screeding structure provides forimproved control of the screeding unit with respect to maintainingdesired grade and elevation with only one control and only one axis asreference a point.

The rigidity of the structure allows for weight reduction by usinglighter materials to form the rigid structure and to utilize planes ofstructures to simplify the unit.

The novel vibrational unit reduces weight, power requirements and avoidsthe necessity for frequent sag adjustments of the vibrational unit.

Also reduces the force required for vibration because of the screedvibrational material thickness and shape. A disadvantage to this screedis that it requires a separate source of motive power to move the screedand to provide power either hydraulic and/or electrical for the augerand other functions.

This screeding assembly allows rotation of the screeding assesmbly as aunit about a single axis and provides an improved vibratory system thatrequires less power and also does not require frequent adjustments ofthe vibratory elements and/or adjustments of the screed surface forsmoothing the material.

These and other objects advantages and features of the invention willbecome more apparent from a study of the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear side view of the screeding apparatus of the presentinvention as mounted on a boom from a motive power apparatus.

FIG. 2 is an end view of the screeding apparatus of the presentinvention.

FIG. 3 is a rear view of the screeding apparatus of the inventionshowing the operating elements.

FIG. 4 is a top view of the invention.

FIG. 5 is schematic view of the electronics of the invention.

FIG. 6 is a schematic view of the fluid controls to various elements ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

Laser Beacon reference Plane Control system for controlling elevation ofscreed assembly including elevation tubes 501 and 502 is substantiallysimilar to that used in U.S. Pat. Nos. 4,655,653 and 4,930,935. Thisincludes prior art and laser receiving mounting masts 501, 502. A laserbeacon 510 receive is removably secured to each of said masts 501 and502.

The necessary data and controls are set forth in Col. 19 and Col. 20lines 59, Col. 19 to line 50, Col. 2. of U.S. Pat. No. 4,930,935 willform part of the control as sensor 600 measures the deviation of thescreed assembly from the desired or present positions to determine theelevation and position of plane between extremities or working surfaceof striker 202 and vibratory unit 300.

Sensor 600 may be a blade level sensor such as a sensor part number421870 and control box 421871 of Trimble which will be placed on endplate 104 as shown in FIG. 1. This level sensor may be preset for limitsof the level or plane as described above and/or to be at a predeterminedelevation of striker and vibratory units.

The proper plane level for grade purposes is maintained by signals fromsensor unit 600 to a corrective cylinder 601 which is affixed to arm 602in a vertical direction thus, rotating the entire screed, striker andvibratory unit about the pivot axis of the auger. The plane between thestriker, and vibratory unit is rotated and changed about a single axis.

Vibratory element 300 comprises an aluminum channel 301, extending thelength of the assembly 100. This channel 301 is supported from mainbeams 101 and 102 by a plurality of vertical members 103 which arevibratoral isolated from said channel 301.

Thus, a small vibratory force furnished by electrical vibration units305 can vibrate channel 301 to smooth the material.

The rigidity of the support elements 103 combined with the relativelythin channel including the surface contact 306 of the channel 301 helpsprevents sag between support elements. This eliminates any adjustmentsto the vibratory element.

Screed assembly 100 is an improved and novel screed assembly with aunitary assembly including main beams 101, 102 and cross support members103 and supportive end plates 104. Supporting rotational auger 201, aplow or striker 202 is positioned in front of auger 201, and novelvibratory element 300 is positioned behind rotational auger 201. Auger201 forms the axis for rotation of the assembly.

Auger 201 assembly is a continuous auger supported from said main beams101 and 102 and end plates 104 as shown in FIG. 2.

The unitary construction of the screed assembly results in the rotationof the entire assembly about the single axis. The striker and vibratoryunits are made of aluminum and a uniform movement of the planedetermined by the extremities of striker 202 and vibrational element orunit 300.

1. An improved screed apparatus for loose or plastic materials formounting on a separate moveable power support means, said screedapparatus including means for mounting said screed assembly on a boom ofsaid power support means the improvement comprising a. The screedassembly being rigid and elongated and including power means, a strikerfur engaging and spreading the material, on a pre-selected plane,rotatable auger means for moving any material above the plane along thedirection of the elongation of said screed assembly, sensing and powermeans for determining deviation from the grade elevation of the screedassembly, and vibration means for engaging, vibrating and smoothing saidmaterial; b. The rigid screed assembly is pivotally mounted about asingle axis extending parallel to direction of elongation whereby thescreed contact with the material may be set and sensed and maintained onpredetermined plane.
 2. The screed apparatus of claim 1, wherein saidpower means for rotating said screed assembly maintains the apre-selected plane through the operative extremities of said striker,said auger and said vibrator at a pre-determined slope/angle andelevation with relation to said material.
 3. The screed apparatus ofclaim 2, wherein said striker and said vibratory units are elements ofsaid screed apparatus made of aluminum.
 4. The screeding apparatus ofclaim 2, wherein said screed includes elevation means for verticallyraising and lowering said screed assembly with respect to saidmaterials.
 5. The screed apparatus of claim 4, wherein said elevationmeans includes a pair of elevation tubes secured to said screed assemblyat opposite ends of said screeding apparatus, power means for raisingand lowering said elevation tubes with respect to said material.
 6. Thescreed apparatus of claim 4, including desired elevation and slopecontrol means responsive to variation from said settings to return andmaintain said settings of level and/or slope values.
 7. The screedingapparatus of claim 2, wherein said vibration means includes a u-shapedchannel member integral with said rigid screed.
 8. The screed apparatusof claim 7, wherein said vibration means includes electric vibrators forvibrating said channel member of claim 7, said channel is vibrationallyisolated from remainder of said screed.
 9. The screed apparatus of claim6, wherein said control means includes power means to rotate said screedassembly.
 10. The screed apparatus of claim 5, wherein said elevationmeans raising and lowering includes a laser beam responsive controlmeans on said screed assembly responsive to a fixed laser referenceplane beam.